Dưa lưới là loại quả mọng nước, có thịt chắc, màu cam bắt mắt, vị ngọt và hương thơm đặc trưng. D... more Dưa lưới là loại quả mọng nước, có thịt chắc, màu cam bắt mắt, vị ngọt và hương thơm đặc trưng. Dưa lưới còn là nguồn cung cấp dồi dào các nhóm vitamin, khoáng chất và các hợp chất có hoạt tính sinh học tốt cho sức khỏe. Mục tiêu của nghiên cứu nhằm tuyển chọn chủng nấm men thương mại thích hợp để ứng dụng trong lên men rượu vang dưa lưới. Đồng thời, nghiên cứu cũng nhằm xác định các điều kiện thích hợp cho quá trình lên men rượu vang bao gồm tỉ lệ pha loãng (1:1, 1:2, 1:3, 1:4), nồng độ enzyme pectinase (0, 0,02, 0,04, 0,06% w/v), hàm lượng chất hòa tan (20, 22, 24, 26°Brix) và pH (4,5, 5,0, 5,5). Kết quả cho thấy sau 7 ngày lên men ở nhiệt độ môi trường (28-32oC), chủng nấm men S. cerevisiae BV818 có khả năng lên men tốt nhất so với các chủng thương mại khác với hàm lượng ethanol đạt 8,54% v/v. Các giá trị tối ưu của từng nhân tố khảo sát cũng được xác định với tỉ lệ pha loãng là 1:1, nồng độ enzyme bổ sung vào dịch quả là 0,02%, hàm lượng chất hòa tan là 26 và pH ban đầu là 5,0. ...
International Journal of Power Electronics and Drive Systems (IJPEDS)
The paper describes field oriented control strategy with space vector pulse width modulation tech... more The paper describes field oriented control strategy with space vector pulse width modulation technique of permanent magnet synchronous motor drive system for an electric vehicle. At first, mathematical models of the motor and the drive system for electric vehicle are presented. In order to obtain high performance drive and maximum motor torque, field oriented control strategy and space vector pulse width modulation technique method are applied to drive system in next section. Speed controller design utilizing the popular zero-pole elimination approach causes large integral constant time in case of small rotational damping constant. The desired-transient-response-based approach is employed to overcome the problem. Performance indices include overshoot, undershoot, steady-state speed error, and total harmonic distortion of stator current, are employed to assess the drive systems with two speed controller design methods. Theoretical assumptions are confirmed via simulations and criter...
TELKOMNIKA (Telecommunication Computing Electronics and Control)
This paper deals with a novel method to achieve the effective performance of the extended Kalman ... more This paper deals with a novel method to achieve the effective performance of the extended Kalman filter (EKF) for the speedy estimate of an induction motor. The real coding genetic algorithm (GA) is used to optimize the components of the covariance matrix in the EKF, thus ensuring the stability and accuracy of the filter in the speed estimation. The advantage of the proposed method is less dependent on the parameters of the induction motor. The content includes the vector control model for induction motor, the speed estimation by modeling the reference frame-model reference adaptive system (RF-MRAS), the current based-model reference adaptive system (CB-MRAS), and the speed estimation with the EKF optimized by genetic algorithm. Simulative studies on the field-oriented controller (FOC) with different operating conditions are performed in Matlab Simulink when the rotor resistance changes in the current speed estimation methods. The simulation results demonstrate the efficiency of the proposed GA-EKF filter compared with other speed estimation methods of induction motors.
Bài viết này trình bày tổng quan các quan niệm về phóng xạ tổng hợp được từ các nghiên cứu trên... more Bài viết này trình bày tổng quan các quan niệm về phóng xạ tổng hợp được từ các nghiên cứu trên thế giới. Dựa vào kết quả tổng hợp được, chúng tôi xây dựng bảng hỏi và khảo sát các quan niệm về phóng xạ trên 505 sinh viên chuyên ngành vật lí ở các trường đại học. Các số liệu thống kê của khảo sát cho thấy rất nhiều sinh viên có quan niệm sai về phóng xạ dù đã được học về phóng xạ hạt nhân. Đã có một số đề xuất phương pháp khắc phục các quan niệm sai này từ các nghiên cứu nói trên, tuy nhiên kết quả vẫn chưa rõ ràng. Kết quả nghiên cứu và những đề xuất của chúng tôi có thể có ích cho những đề tài hay những nghiên cứu tiếp theo về việc dạy học nhằm khắc phục những quan niệm sai về phóng xạ.
Edelweiss Journal of Food Science and Technology, 2019
At the present time, polyphenolic compounds have attracted great interest due to their roles in t... more At the present time, polyphenolic compounds have attracted great interest due to their roles in the prevention of degenerative diseases and have used as the input material for manufacturing functional foods, nutraceutical and pharmaceutical products. Previous researches have revealed the avocado seed is rich source of polyphenolic compounds with antioxidant and antimicrobial activities; which they could be used as a source of potent natural ingredients and additives. In this study, extraction factors of polyphenols were optimized for recovery yield by using response surface methodology and the obtained polyphenol rich solution was encapsulated with different coating agents (Maltodextrin-MD and Gum Arabic-GA) as well as their mixtures. A Box-behnken design was used to investigate the effects of three independent variables including ethanol concentration (X1:35-65%, v/v), solvent to solid ratio (X2:8-12, v/w) and extraction time (X3:1.0-3.0 h). The result shown that the optimized extr...
TELKOMNIKA (Telecommunication Computing Electronics and Control), 2021
The paper deals with application of Kalman filter in induction motor drive using pulse-width modu... more The paper deals with application of Kalman filter in induction motor drive using pulse-width modulation direct torque control (PWM-DTC). In the first part, the conventional PWM-DTC drive is described and Kalman filter is utilized to filter components of stator current vector those are assumed to be disturbed by white noise. The second part contains simulation results that are obtained in different cases of load torque, process and measurement noise covariances. The integral time absolute error (ITAE) performance index, undershoot, ripple of important quantities are used to compare the conventional drive structure and proposed drive structure with Kalman filter. The simulation results confirm the expected dynamic response of the proposed structure.
Three new xanthones, pedunxanthones D-F (1-3), along with ten known compounds, were isolated from... more Three new xanthones, pedunxanthones D-F (1-3), along with ten known compounds, were isolated from a chloroform extract of the pericarp of Garcinia pedunculata. Their structures were determined using spectroscopic techniques. Cytotoxicity against HeLa and NCI-H460 cells of the isolated compounds using an SRB assay was evaluated with pedunxanthone D (1) as the most active compound (IC 50 24.9 AE 0.4 and 26.1 AE1.5 mg/ml, respectively).
2013 International Conference on Soft Computing and Pattern Recognition (SoCPaR), 2013
Wi-Fi localization system based on RSSI is the best candidate for indoor device-tracking in compa... more Wi-Fi localization system based on RSSI is the best candidate for indoor device-tracking in comparison with other systems based on GPS, RFID, infrared and image processing. This paper presents Wi-Fi localization system based on a Wi-Fi routers' network for tracking the device position indoors such as buildings, university campus, skyscrapers and other places where Wi-Fi is present including shopping malls. Our system consistently collects the current location and status of the tracked devices and sends them periodically to the users' central office for further processing and display. If there are any unexpected changes of the tracked device's position, an immediate notification is sent via email to the administrator for security purposes. The system operates real-time with high accuracy. Contributions are made in software development and Wi-Fi tags attachments design.
This paper proposes a mixed H 2 /H ∞ optimal PID controller with a genetic algorithm based on the... more This paper proposes a mixed H 2 /H ∞ optimal PID controller with a genetic algorithm based on the dynamic model of a Rotational Inverted Pendulum (RIP) and applies it for balancing control. In the dynamic model of the rotational inverted pendulum with perturbation, the proposed controller guarantees robust and optimal performance to the stabilization of the rotational inverted pendulum. A genetic algorithm was used to obtain parameters for the PID controller that satisfies the mixed H 2 /H ∞ constraint. To implement the proposed controller, a control system based on microcontroller dsPIC30F4011 was developed. Experimental results are shown to prove the performance of the proposed controller when changing the weight and shape of pendulum.
The genus Garcinia (Guttiferae) has been of increasing interest due to its medicinal value for th... more The genus Garcinia (Guttiferae) has been of increasing interest due to its medicinal value for the treatment of different kinds of illnesses such as vomiting, swelling, tapeworms, dysentery, chronic diarrhoea, piles, pains and heart complaints (Kumar and Baslas, 1980), and due to the continuous isolation of both chemically and biologically interesting phenolic metabolites (Baliga et al., 2011; Obolskiy et al., 2009; Yang et al., 2010). Garcinia schomburgkiana PIERRE is a medium-sized tree used in folk medicine of Viet Nam for the treatment of coughs and menstrual disturbances (Pham, 2006). Previously, the isolation of a mixture of benzophenones was reported from the stems of G. schomburgkiana (Fun et al., 2006). In this paper, we describe the isolation and structure elucidation of two new xanthones, 6-O-demethyloliverixanthone and schomburgxanthone, together with six known xanthones, from the bark of this species collected in the southern part of Viet Nam.
Dưa lưới là loại quả mọng nước, có thịt chắc, màu cam bắt mắt, vị ngọt và hương thơm đặc trưng. D... more Dưa lưới là loại quả mọng nước, có thịt chắc, màu cam bắt mắt, vị ngọt và hương thơm đặc trưng. Dưa lưới còn là nguồn cung cấp dồi dào các nhóm vitamin, khoáng chất và các hợp chất có hoạt tính sinh học tốt cho sức khỏe. Mục tiêu của nghiên cứu nhằm tuyển chọn chủng nấm men thương mại thích hợp để ứng dụng trong lên men rượu vang dưa lưới. Đồng thời, nghiên cứu cũng nhằm xác định các điều kiện thích hợp cho quá trình lên men rượu vang bao gồm tỉ lệ pha loãng (1:1, 1:2, 1:3, 1:4), nồng độ enzyme pectinase (0, 0,02, 0,04, 0,06% w/v), hàm lượng chất hòa tan (20, 22, 24, 26°Brix) và pH (4,5, 5,0, 5,5). Kết quả cho thấy sau 7 ngày lên men ở nhiệt độ môi trường (28-32oC), chủng nấm men S. cerevisiae BV818 có khả năng lên men tốt nhất so với các chủng thương mại khác với hàm lượng ethanol đạt 8,54% v/v. Các giá trị tối ưu của từng nhân tố khảo sát cũng được xác định với tỉ lệ pha loãng là 1:1, nồng độ enzyme bổ sung vào dịch quả là 0,02%, hàm lượng chất hòa tan là 26 và pH ban đầu là 5,0. ...
International Journal of Power Electronics and Drive Systems (IJPEDS)
The paper describes field oriented control strategy with space vector pulse width modulation tech... more The paper describes field oriented control strategy with space vector pulse width modulation technique of permanent magnet synchronous motor drive system for an electric vehicle. At first, mathematical models of the motor and the drive system for electric vehicle are presented. In order to obtain high performance drive and maximum motor torque, field oriented control strategy and space vector pulse width modulation technique method are applied to drive system in next section. Speed controller design utilizing the popular zero-pole elimination approach causes large integral constant time in case of small rotational damping constant. The desired-transient-response-based approach is employed to overcome the problem. Performance indices include overshoot, undershoot, steady-state speed error, and total harmonic distortion of stator current, are employed to assess the drive systems with two speed controller design methods. Theoretical assumptions are confirmed via simulations and criter...
TELKOMNIKA (Telecommunication Computing Electronics and Control)
This paper deals with a novel method to achieve the effective performance of the extended Kalman ... more This paper deals with a novel method to achieve the effective performance of the extended Kalman filter (EKF) for the speedy estimate of an induction motor. The real coding genetic algorithm (GA) is used to optimize the components of the covariance matrix in the EKF, thus ensuring the stability and accuracy of the filter in the speed estimation. The advantage of the proposed method is less dependent on the parameters of the induction motor. The content includes the vector control model for induction motor, the speed estimation by modeling the reference frame-model reference adaptive system (RF-MRAS), the current based-model reference adaptive system (CB-MRAS), and the speed estimation with the EKF optimized by genetic algorithm. Simulative studies on the field-oriented controller (FOC) with different operating conditions are performed in Matlab Simulink when the rotor resistance changes in the current speed estimation methods. The simulation results demonstrate the efficiency of the proposed GA-EKF filter compared with other speed estimation methods of induction motors.
Bài viết này trình bày tổng quan các quan niệm về phóng xạ tổng hợp được từ các nghiên cứu trên... more Bài viết này trình bày tổng quan các quan niệm về phóng xạ tổng hợp được từ các nghiên cứu trên thế giới. Dựa vào kết quả tổng hợp được, chúng tôi xây dựng bảng hỏi và khảo sát các quan niệm về phóng xạ trên 505 sinh viên chuyên ngành vật lí ở các trường đại học. Các số liệu thống kê của khảo sát cho thấy rất nhiều sinh viên có quan niệm sai về phóng xạ dù đã được học về phóng xạ hạt nhân. Đã có một số đề xuất phương pháp khắc phục các quan niệm sai này từ các nghiên cứu nói trên, tuy nhiên kết quả vẫn chưa rõ ràng. Kết quả nghiên cứu và những đề xuất của chúng tôi có thể có ích cho những đề tài hay những nghiên cứu tiếp theo về việc dạy học nhằm khắc phục những quan niệm sai về phóng xạ.
Edelweiss Journal of Food Science and Technology, 2019
At the present time, polyphenolic compounds have attracted great interest due to their roles in t... more At the present time, polyphenolic compounds have attracted great interest due to their roles in the prevention of degenerative diseases and have used as the input material for manufacturing functional foods, nutraceutical and pharmaceutical products. Previous researches have revealed the avocado seed is rich source of polyphenolic compounds with antioxidant and antimicrobial activities; which they could be used as a source of potent natural ingredients and additives. In this study, extraction factors of polyphenols were optimized for recovery yield by using response surface methodology and the obtained polyphenol rich solution was encapsulated with different coating agents (Maltodextrin-MD and Gum Arabic-GA) as well as their mixtures. A Box-behnken design was used to investigate the effects of three independent variables including ethanol concentration (X1:35-65%, v/v), solvent to solid ratio (X2:8-12, v/w) and extraction time (X3:1.0-3.0 h). The result shown that the optimized extr...
TELKOMNIKA (Telecommunication Computing Electronics and Control), 2021
The paper deals with application of Kalman filter in induction motor drive using pulse-width modu... more The paper deals with application of Kalman filter in induction motor drive using pulse-width modulation direct torque control (PWM-DTC). In the first part, the conventional PWM-DTC drive is described and Kalman filter is utilized to filter components of stator current vector those are assumed to be disturbed by white noise. The second part contains simulation results that are obtained in different cases of load torque, process and measurement noise covariances. The integral time absolute error (ITAE) performance index, undershoot, ripple of important quantities are used to compare the conventional drive structure and proposed drive structure with Kalman filter. The simulation results confirm the expected dynamic response of the proposed structure.
Three new xanthones, pedunxanthones D-F (1-3), along with ten known compounds, were isolated from... more Three new xanthones, pedunxanthones D-F (1-3), along with ten known compounds, were isolated from a chloroform extract of the pericarp of Garcinia pedunculata. Their structures were determined using spectroscopic techniques. Cytotoxicity against HeLa and NCI-H460 cells of the isolated compounds using an SRB assay was evaluated with pedunxanthone D (1) as the most active compound (IC 50 24.9 AE 0.4 and 26.1 AE1.5 mg/ml, respectively).
2013 International Conference on Soft Computing and Pattern Recognition (SoCPaR), 2013
Wi-Fi localization system based on RSSI is the best candidate for indoor device-tracking in compa... more Wi-Fi localization system based on RSSI is the best candidate for indoor device-tracking in comparison with other systems based on GPS, RFID, infrared and image processing. This paper presents Wi-Fi localization system based on a Wi-Fi routers' network for tracking the device position indoors such as buildings, university campus, skyscrapers and other places where Wi-Fi is present including shopping malls. Our system consistently collects the current location and status of the tracked devices and sends them periodically to the users' central office for further processing and display. If there are any unexpected changes of the tracked device's position, an immediate notification is sent via email to the administrator for security purposes. The system operates real-time with high accuracy. Contributions are made in software development and Wi-Fi tags attachments design.
This paper proposes a mixed H 2 /H ∞ optimal PID controller with a genetic algorithm based on the... more This paper proposes a mixed H 2 /H ∞ optimal PID controller with a genetic algorithm based on the dynamic model of a Rotational Inverted Pendulum (RIP) and applies it for balancing control. In the dynamic model of the rotational inverted pendulum with perturbation, the proposed controller guarantees robust and optimal performance to the stabilization of the rotational inverted pendulum. A genetic algorithm was used to obtain parameters for the PID controller that satisfies the mixed H 2 /H ∞ constraint. To implement the proposed controller, a control system based on microcontroller dsPIC30F4011 was developed. Experimental results are shown to prove the performance of the proposed controller when changing the weight and shape of pendulum.
The genus Garcinia (Guttiferae) has been of increasing interest due to its medicinal value for th... more The genus Garcinia (Guttiferae) has been of increasing interest due to its medicinal value for the treatment of different kinds of illnesses such as vomiting, swelling, tapeworms, dysentery, chronic diarrhoea, piles, pains and heart complaints (Kumar and Baslas, 1980), and due to the continuous isolation of both chemically and biologically interesting phenolic metabolites (Baliga et al., 2011; Obolskiy et al., 2009; Yang et al., 2010). Garcinia schomburgkiana PIERRE is a medium-sized tree used in folk medicine of Viet Nam for the treatment of coughs and menstrual disturbances (Pham, 2006). Previously, the isolation of a mixture of benzophenones was reported from the stems of G. schomburgkiana (Fun et al., 2006). In this paper, we describe the isolation and structure elucidation of two new xanthones, 6-O-demethyloliverixanthone and schomburgxanthone, together with six known xanthones, from the bark of this species collected in the southern part of Viet Nam.
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